Bert Nordberg, the company's president, admitted that Sony Ericcson had suffered a turbulent year. He said the new range of phones would be focused on communication and entertainment.

The Android-based devices - the X10 Mini and X10 Mini Pro - are smaller than a credit card, and feature four "hot" corners so that users can hold the device in one hand while still accessing menus and key functions.

Both devices have a touch-screen interface, and the X10 Mini Pro also has a slide-out Qwerty keyboard.

Communication is grouped together, so that users can see all of their text messages, emails, Facebook and Twitter interaction with a contact in one place.

"There has been an enormous buzz around Xperia X10, so it is really exciting to be unveiling compact versions of this powerful proposition," Rikko Sakaguchi, a senior Sony Ericsson executive, told the audience at Mobile World Congress.

"Some of the obituaries that have been written on Sony Ericsson may be a little premature," said Ben Wood, an analyst at CCS Insight. "There is no doubt the company still has challenges, but these new products are a first step to help fuel a recovery."